Cell cycle

How do cells determine wether to divide or not to divide? 
The way it determines to divide is by a signal to divide or not to divide.

What are the mechanics of the cell cycle and how is it controlled?
It is controlled by the proteins in the cell.

How does cancer develop? 
it develops when a cell decides to divide on its own without a signal to divide.

What roll do proto-oncogenes and tumor suppresser play in controlling the cell cycle?
The roll proto-oncogenes play is that they stimulate cell division and the accelerator.

How do cancer treatments work and why they are not good for the body?
 cancer treatments use high doses of radiation targeted at the cancer cells. The reason they are not good for the body is because of the radiation.

Why does a multicellular organism need to control and coordinate cell division?  
It needs to control and coordinate cell division because some cells don't need to divide all the time.

What might be the consequences of uncontrolled cell division in a multicellular organism?
The consequences of uncontrolled cell division in a multicellular organism is that it can cause mutation and the cells won't divide.

What does it mean when we say that there are several “checkpoints” that occur during the cell cycle?
it means that cells have to go through a process to be able to divide.

Give an example of an external signal that regulates cell division and explain how it works.
Internal controls: Protein molecules vary concentrations during the cell cycle.

Compare and contrast the functions of proto-oncogenes and tumor suppressor genes.Give an example of each and explain why mutations in these genes can lead to cancer.
Proto-oncogenes: stimulates cell division, go sign for the cell cycle, mutated cells always on.  

Proto-oncogenes can lead to cancer because the mutated genes will still be active and will keep on dividing.

Tumor suppressor genes: Inhibits cell division, the brake peddle of the cell cycle, keeps mutated cells off.

Tumor suppressor genes can lead to cancer because if it does not work properly it can cause it to grow out of control.

Microscope lab

In this lab I learned how to use a microscope and then do a test on it so me and my friends chose our own cell and we would focus on it after that we took a test.

Some cool pictures 

On the left is moss. In the middle is asparagus. On the right is a frog egg.

PKU (Phenylketonuria)

1. What enzyme is most commonly defective in people with phenylketonuria?

The enzyme that is the most commonly defective in people with phenylketonuria is enzyme Phenylalanine Hydroxylase.

2. What reaction does this enzyme catalyze? (What is the substrate and what product is produced?)

It causes mental retardation because it changes cells inside the brain.

3. Describe the symptoms of phenylketonuria.

lighter hair and skin a smaller than normal head and the skin has a musty odor.

4. What causes the symptoms of PKU, the lack of a substance or the buildup of one? Explain. 

The causes of the symptoms is that it causes the enzyme to not work properly by mutating the gene.

5. How common is phenylketonuria? How is it treated? 

1 in 10,000 births in caucasians and east asians, 1 in 2,600 in turks, 1 in 4,500 in irish, 1 in 143,000 in japanese, and it is exceedingly rare in africans.

The way PKU is treated is by having a low protein diet as soon as the disorder is diagnosed and stay on that diet as long as possible.

Cited Sources: http://www.ygyh.org
http://www.nspku.org

Pick Your Poison: Ricin

1.) Where is this substance found or produced? It is found in a castor bean 

2.) What kind of substance is it? Powder

3.) What are the specific molecules that it acts upon? It acts upon the cytosol and can inactivate over 1,500 ribosomes per minute and kill the cell.

4.) What are the symptoms of exposure to this substance? 

By ingestion causes vomiting, diarrhea, dehydration, low blood pressure, seizures, and liver. 

By inhalation causes difficulty breathing, fever, cough, nausea, heavy sweating, fluid in lungs and low blood pressure.

5.) How is exposure to this substance treated? If ricin gets on you get rid of your clothes and wash yourself by using large amount of soap and water. Then put away your clothes in a bag using a tong or any other tool then seal it into another bag and the local or state health department will take care if the rest.

Cited sources:  http://www.medicinenet.com/ricin/article.htm
http://poisonousplants.ansci.cornell.edu/toxicagents/ricin.html

Osmosis Lab

Question: What does water do in a osmosis operation?

Procedure: Have two beakers, salt, water, two dialysis tubes, and a weight . Fill one of the beakers with salt and water and one beaker with just water. Grab a dialysis tube and pour salt into it the dialysis tube then grab another dialysis tube and pour water into it. weigh the two dialysis tubes before you put it into the the beaker then put the one with just salt into the beaker that has just water and then the dialysis tube with just water put it into the beaker with salt and water. Then after a day take the two dialysis tubes out of the beakers and weigh them again. The dialysis tube with salt should weigh more than the dialysis tube with just water.

Claims: The dialysis tube with salt weighs more than the one with water because of osmosis.

Evidence: 

Research: Osmosis is when molecules move through a semi permeable membrane into a region of higher solute concentration, in the direction that tends to equalize the solute concentrations on the two sides.

Reflection: I learned how osmosis can affect a cell membrane.

Cell membrane

In this lab I chose people into my group and we had to find a picture of a cell-membrane in google images and draw it the reason we did this was so we can understand what a cell-membrane is and learn what can pass through a cell-membrane and what can't go through a cell membrane.

Diffusion and Osmosis Lab

Question: Why couldn't the starch get out?

Procedure: have a beaker, dialysis tube, test-tape (For recording Glucose levels), glucose, and starch, and Iodine. Fill the beaker with water almost at the top of the beaker and add a bit of iodine. Now test the beaker with the test tape and record the color of the mixture. Then grab a dialysis tube and open one side and then tie the bottom next fill it with 15% glucose and 1%starch then test it with the test tape and now tie the top of the bag and put it in the beaker. Next, wait 30minutes or wait for a distinct color change and record the beaker and dialysis tube again with the test tape.

Claims: the reason the starch didn't get out of the dialysis tube because the size of the molecules were too big for it to pass through the tiny pores of the dialysis tube.

Evidence: The before and after pictures 

Research: Diffusion is the movement of particles from an area of high concentration to an area of lower concentration. Osmosis is the diffusion of water from a hypotonic solution across and selectively permeable membrane.  

Reflection: Now I know that not everything can pass through a membrane.


Hypotonic definition: having a lower osmotic pressure than a particular fluid, typically a body fluid or intracellular fluid.

Permeable definition: (of a material or membrane) allowing liquids or gases to pass through it.